We launched a new series on the blog in October. Once a month, we are sharing with you a presentation given at the 2017 Allen D. Leman swine conference, on topics that the swine group found interesting, innovative or that lead to great discussions.

Our third presented is from Dr. Jim Lowe from the University of Illinois on the movements of cull sows in North America and what it implies in terms of disease transmission.

Key points:

The National Swine Reproduction Guide (NSRG; U.S. Pork Center of Excellence, Des Moines, IA) is a valuable tool to help producers utilize data analysis to troubleshoot reproductive problems in a herd or farm.

Analysis of farrow-to-wean farms within a North Carolina production system revealed extended wean-to-service interval of first-parity sows and poor performance of second-parity sows. NSRG recommendations include reviewing lactation diet composition and first-parity sow lactation feed intake.

Reproductive data from nine farms within one production system from 2011 to 2015 were obtained. Average Total Number Born (TNB) for the production system was 12.4 piglets born per litter, yet litter size was lowest in second-parity sows. Greater than 24% of second-parity sows failed to achieve the decision boundary criteria of 11.5 TNB. Within first-parity sows, 73% of the contemporary groups had greater than 10% of their sows failing to return to estrus within 10 days of weaning.

The following recommendations to improve TNB and reduce Weaning-to-Service Interval (WSI) were created following consultation of the NSRG:

Limit cross-fostering onto first-parity sows

Review lactation diet composition, particularly amino acid content;

Identify methods to promote first-parity sow lactation feed intake. If economically
feasible, farms may also consider breeding sows displaying estrus 7 and 8 days post-weaning on their next cycle.

The first week-end of December was the Conference of Research Workers in Animal Diseases in Chicago. Several of the swine group graduate students were presenting their work and received an award.

First, Frances Shepherd received the award for best oral presentation in the Enteric Diseases category for her presentation titled Variability and bioinformatic analysis of porcine rotavirus B and C illustrate potentially important immunological sites. Frances’ advisers are Dr. Douglas Marthaler and Dr. Michael Murtaugh.

Then, Dr. Robert Valeris received the best poster award in the Veterinary Epidemiology and Preventative Medicine category for presenting Survival analysis of protocols for eradication of Mycoplasma hyopneumoniae in swine farms.

This month in the National Hog Farmer, Drs. Carles Vilalta, Juan Sanhueza, and Montse Torremorell share a project instigated by the late Dr. Bob Morrison regarding the use of processing fluids to make a PRRSV diagnosis.

The improvement of sampling and diagnostics techniques has made sampling on the farm an easier task with the use of pooled serums or oral fluids samples for example.

One of the ways to get cheaper, more sensitive and quicker techniques would be to use routine chores, such as piglet processing, since castration and tail docking are part of the regular procedures in sow farms.

The goal of this study was to evaluate the accuracy of the processing fluids (the liquid accumulated at the bottom of the pail when farmers collect tails and testicles during routine procedures) by real-time polymerase chain reaction to assess PRRSV status in a sow herd.

The key points from the studies were:

• Using processing fluids as a diagnostic tool can help us to detect lower PRRS prevalence in the herd.
• Testicles and tails should be collected in a pail as they are potential spreaders of PRRS in the farrowing room.
• We should target young parity sows for PRRSV sampling.

Key Points

Each year approximately 3% of the sow farms have a PRRS outbreak during the summer.

The incidence of summer PRRS breaks has been constant over the last 9 years.

There are geographical areas with higher or lower risk of summer breaks.

Figure 1. PRRS summer outbreak incidence per year between 2009 and 2017.

A summer outbreak was defined as a PRRS case that happened between June 21st and September 21st of the year. The mean incidence of PRRS summer outbreaks was 3.2% between 2009 and 2017, ranging between 1.6% and 4.4%. The trend was stable among the years. (Figure 1) Not all areas are equal against summer outbreaks. Indeed, the region of Southern Minnesota – Northern Iowa is more at risk of outbreaks than others like Southern Iowa or Eastern North Carolina. (Figure 2)

The first week-end in December is usually the time of the North American PRRS symposium. This year did not upset the tradition but this time, the conference was in collaboration with the National Swine Improvement Federation.

The 2017 NA PRRS meeting was dedicated to Dr. Bob Morrison.

The meeting was dedicated to our friend and colleague Dr. Bob Morrison. A memorial fellowship organized by Dr. Montse Torremorell (U of MN) and Dr. Joan Lunney (USDA) provided travel support to future scientists who wish to follow in his footsteps.

Stephen Gerike from the Pork Checkoff shared information on the state of pork products used in restaurant. Bacon represents 20% of products used but is still growing (+4% since last year).

Overall, 82% of restaurant customers eat the same or larger amount of pork which is a good trend for the industry. Mr. Gerike also shared the efforts done by Pork Checkoff to convince consumers to not overcook their pork. Reminder: 145F is safe. “Cook your pork like you cook your steak!”

The University of Minnesota was well represented during the conference. Dr. Montse Torremorell moderated the Saturday morning session on PRRS in the field. Drs. Cesar Corzo, Carles Vilalta and Juan Sanhueza shared the updates on the Morrison Swine Health Monitoring Program as well as regarding the studies that they are involved with. Take away messages:

MSHMP is now collecting information from 50% of the sows in the United States.

Based on this data, 58% of the farms breaking with PRRSV today will break again within a year.